Little is known about the effects of malpractice claims in the practice of dentistry, a growing problem in all health professions. Past studies have focused on medical malpractice and have relied on prevalence data (often unvalidated) and, almost always, on aggregate measures. A cross sectional design will be employed to estimate the prevalence of filed as well as of paid claims, to investigate the prevalent severity distribution of paid claims and to ascertain the relative contribution of the legal environment, claims experience and insurance and the dental market to an explanatory model of dentist behavior. A sample of 3875 general practice dentists, stratified by state, will be randomly drawn from the American Dental Association (ADA) Directory and surveyed. Information on claims experience and severity will be self-reported by the dentists and will be cross-validated by insurance company records on a sub-group. The survey will also inquire about the dentist's insurance coverage, practice form, practice treatment mix, care process, prices and practice beliefs. State specific data on malpractice laws will be collected from public records. Data on coverage limits, types of policies and procedures will be obtained from insurance carriers. This study will help estimate the nation-wide magnitude of the malpractice problem in dentistry. It will be the first investigation to focus on dentist behavior.